1. Field of the Invention
The present invention relates to a fuel injection control device for a diesel engine, and more specifically relates to a fuel injection control device for a diesel engine for controlling the first fuel injection command soon after a cranking at the time of starting the engine.
2. Related Art
A fuel injection control device for a diesel engine includes a common-rail fuel injection control device. In the common-rail fuel injection control device, fuel is accumulated into a common rail by a high-pressure pump, and the fuel is injected from an injector into a combustion chamber by opening and closing a solenoid valve. The fuel injection timing and fuel injection quantity are controlled by the energization of the solenoid valve in the injector, depending on the specified engine rotating speed, the load or the like. Cranking is started by a starter, and then a cylinder engine in which the fuel is first injected is determined by a cylinder engine determining sensor as well as a fuel injection command signal is issued from an engine control unit (hereinafter, referred to as “ECU”) to the solenoid valve in the injector, whereby the engine is started. Briefly, the fuel injection is started immediately after the cranking has been started and the cylinder engine is determined. In order to increase the rail pressure of the common rail at the time of starting the engine, a discharge rate of the fuel from the high-pressure pump is set up to be maximized shortly after the cranking. With regard to the common-rail fuel injection device mentioned above, the following fuel injection devices are disclosed, wherein the fuel injection is divided into a main injection and a pilot injection before the main injection, so as to slack a combustion by the main injection (for example, see Patent Literature 1), so as to control the pilot injection (for example, see Patent Literature 2) or so as to reduce the amount of white smoke at the time of starting the engine by further injecting a small amount of fuel before the pilot injection or the like (for example, see Patent Literature 3).
Patent Literature 1: the Japanese Patent Laid Open Gazette 3473211
Patent Literature 2: the Japanese Patent Laid Open Gazette 3418996
Patent Literature 3: the Japanese Patent Laid Open Gazette 3580099